A new report presented at the European Respiratory Society's Annual Congress in Amsterdam over the weekend claims that individuals who regularly bicycle in major cities like London and Amsterdam have increased levels of black carbon in their respiratory systems. A condition commonly associated with turn-of-the-century industrial revolution processes, black lung is still persistent in the right environments. City cyclists are at a higher risk simply because they are breathing heavier in a relatively polluted environment.

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Black carbon refers to inhalable soot particles produced by the combustion of fossil fuels, similar to the particles that line chimneys. A wide range of health effects are associated with black carbon and include heart attacks and reduced lung function because it lines and constricts the airways.

Ironically, an individual's choice to have a healthy commute can possibly result in deteriorating respiratory health. The researchers who presented the report, led by Professor Jonathon Grigg from Barts and the London School of Medicine, made this hypothesis and aimed to prove it through surveying and medically sampling healthy adult bicycle commuters. They took samples of a lower airway cell called the airway macrophage, a cell that clings to the surface of the air passage and absorbs foreign material.

They took these samples from five healthy adult bicyclists and compared the same taken from five healthy adult pedestrians. All individuals sampled were screened for health criteria such as non-smoking, and all were between ages 18 and 40.

The results revealed that the cyclists had 2.3 times more black carbon in their lungs compared to the pedestrians. According to one of the researchers, Chinedu Nwokoro, "The results of this study have shown that cycling in a large European city increases exposure to black carbon. This could be due to a number of factors including the fact that cyclists breathe more deeply and at a quicker rate than pedestrians while in closer proximity to exhaust fumes, which could increase the number of airborne particles penetrating the lungs. Our data strongly suggest that personal exposure to black carbon should be considered when planning cycling routes. Whether cycling by healthy individuals is in itself associated with adverse health effects is currently being assessed in a larger ongoing study."